Measurement Definitions for Land Surveyors
measurement—1 A measuring or being measured; mensuration. 2 Extent, quality, or size as determined by measuring; dimension. 3A system of measuring or of measures.
measurement, double proportionate—A method for restoring a lost corner of four townships or a lost interior comer of four sections. It is based on the principle that monuments north and south should control the latitudinal position of a lost corner and monuments east and west should control the longitudinal position. In this method the influence of one identified original corner is balanced by the control of a corresponding original corner upon the opposite side of a particular missing corner, which is to be restored, each identified original corner being given a controlling weight inversely proportional to its distance from the lost corner. See also measurement, proportionate; measurement, single proportionate.
measurement, electronic distance (EDM)—Measurements made with devices that compare the phase difference between transmitted and returned (i.e., reflected or retransmitted) electromagnetic waves, of known frequency and speed, or the round-trip transit time of a pulsed signal, from which distance is computed. A wide range of such equipment is available for surveying and navigational use. EDM or EDMI (electronic distance measuring) instruments currently in use are electro-optical, transmitting either Laser or infrared light.
measurement, fractional instantaneous phase [GPS]—A measurement of the carrier beat phase which does not include any integer cycle count. It’s value is between zero and one cycle.
measurement, proportionate—A measurement that applies an eve distribution of a determined excess or deficiency of measurement ascertained by retracement of an established line, to provide concordant relations between all parts. See also measurement, double; measurement, single proportionate.
measurement, single proportionate—A method of proportioning measurements in the restoration of a lost corner whose position determined with reference to alignment in one direction. Examples such corners are quarter-section corners on the line between two section corners, all corners on standard parallels, and all intermediate positions on any township boundary line. The ordinary field problem consists distributing the excess of deficiency between two existing corners such a way that the amount given to each interval shall bear the same proportion to the whole difference as the record length of the interval bears to the whole distance. After having applied the proportionate difference to the record length of each interval, the sum of the several parts will equal the new measurement of the whole distance. See also measurement, proportionate; measurement, double proportionate.
measurements, differenced [GPS]—Many combinations of differenced measurements are possible: between-epoch difference, between-frequency difference, between-receiver difference, or between-satellite difference. The type of differences, and its order, should be specified when describing a processing method, e.g., receiver-satellite double differences.
Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.
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